Compounding dynamo-electric machines.



Patented Dec. I6; I902. E. B. RAYMOND.

COMPOUNDING DYNAMO ELECTRIC MACHINES.

(Application filed Oct. 31, 1896.)

3 Sheets-Sheet I.

(No Model.)

No. 7l6,l02. Patented Dec. l6, I902.

E. B. RAYMOND. I GUMPOUNDING DYNAMO ELECTRIC MACHINES.

(Application filed. Oct. 31, 1896.)

(No llodal.) 3 Sheets-Sheet 2.

"mun 1 Patented Dec. l6, I902.

E. B. RAYMOND. OOIPOUNDING DYNAMO ELECTRIC MACHINES.

' (Application filed Oct. 31, 1896.) (No Model.) 3 Sheets-Sheet 3.

m; warns wzrzns w PHOTO-K IYHQ. WASHINGTON, n r

UNITED STATES PATENT OFFIC EDVARD B. RAYMOND, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, A CORPORATION OF NEVVYORK.

COMPOUNDING DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 716,102, dated December 16, 1902.

Application filed October 31, 1896. SerialNo. 610,680. (No model.)

To all whom it may concern.-

Be it known that I, EDW'ARD B. RAYMOND, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of NewYork,haveinvented certain newand useful Improvements in Compounding Dynamo- Electric Machines, (Case No. 436,) of which the following is a specification.

My invention relates to apparatus for 00mpounding dynamo-electric machines, and is particularly applicable to those of the alternating-current type. It dispenses with the use of a commutator and series field-winding and avoids the sparking necessarily involved in the commutation of the line-current or any part thereof.

It is well known that as the load on a generator increases the resistance drop in the armature and in theline increases, which causes the translating devices to receive a lower voltage. It is also a fact that a similar effectis produced in an alternating-current system by an increase in the lag of the current. The principal reasons for this latter effect I understand to be, first, that the lagging current tends to demagnetize the generator field-magnets; second, that the resultant electromotive force supplied to the translating devices is diminished by the counter electromotive force of 0' self-induction, and, third, that the inductive drop in the armature and in the feeders is greater with a lagging current.

It is possible by the use of my invention to regulate the machine to which my improvements are applied in such a Way as to compensate both for any change in the quantity of the armature-current and also for any increase or decrease in the lag of the current in the system. Itis also possible to adjust either for what is known as straight compounding or for any desired percentage of overcompounding, so that the voltage either at the terminals of the machine or at any selected point in the system may be kept constant whatever may be the load or the lag.

My improvements are also applicable to circuits regulated by feeder-regulators or like devices separate from the generator and to any other use in which the conditions of the circuit are to be controlled in accordance with the voltage, current, or lag.

troller.

To these ends my invention consists of an apparatus for generating a current Whose volume or voltage depends upon the conditions of the circuit to be controlled and a new mechanical regulating device responsive to the changes in such current, as will be hereinafter more fully described and claimed.

I have illustrated certain embodiments of my invention in the accompanying drawings, in which Figure 1 is a plan, and Fig. 2 a side elevation, of my improved regulator in its preferred form. Figs. 3 and 4 are respectively a perspective and a crosssection of a portion of the same. Figs. 5 and 6 are diagrams illustrating the relations of the various currents and electromotive forces in the system under different conditions. Fig. 7 is a diagrammatic illustration of the connections of myimproved compounding apparatus applied to the regulation of an alternating-current dynamo-electric machine. Fig. 8 is a diagram of a similar arrangement for adjusting a feeder regulator, and Fig. 9 shows my improved regulator applied to straight compounding.

In Figs. 1 and 2, A isa rheostat or other con- B is a solenoid, and O is the core of the solenoid. D, Figs. 1, 2, 3, and 4, is a rack-bar connected with the arm of the rheostat, as shown- This rack-bar is notched to form a ratchet to engage with the pawls G G, which are reciprocated by an eccentric G driven by a shaft and pulley K, connected to any suitable motor device, the latter not being illustrated. By the rotation of the pulley K the eccentric G is caused to move the pawls G G backward and forward along the notches of the bar D. The core O is attached to the lever E connected to one of the pawls G, which is connected to the other pawl G through an adjusting device G The weight of this core is counterbalanced by the weight F upon an extension of the lever. The arm 5 E of the lever is connected to a spring E the other end of the spring being secured to an adjusting device E carried upon the fixed portion I of the apparatus. A detent H is provided with a suitable clip H, so that by ion its rotation around the shaft h the pawls G G may be removed from engagement with the rack. When the current in the solenoid B weakens, the core 0 is drawn upward by the action of the spring E the pawl G is brought into engagement with the bar D, and the switch-arm of the rheostat is actuated to cut out the resistance. \Vhen the current in the solenoid Bstrengthens, the reverse action takes place.

In Fig. 7 I have shown at L an alternatingcurrent dynamo-machine excited by the direct-curent generator M. In series with the field magnetic windings L of the alternator and with the armature of the exciter orin any other relation in which a change of resistance will affect the voltage of the main machine is placed the current-controller or rheostat A, controlled by the solenoid B, as above described. The solenoid B is supplied with current from the secondaries n a of the two transformers N and N. In the form shown the two secondaries are connected in series. The transformer N has its primary in series with the armature-circuit of the main machine and is shunted by theresistanceR, connected to the points a b. This resistance should preferably be entirely non-inductive. The transformerN hasits primaryin shunttothe mains. A non-inductive resistance S may beinserted in the circuit of the solenoid B. As will appear below, the armature-current of the alternator divides between the primary of N and the resistance R, and the amount of this resistance determines the amount of the compounding and its relation to the inductive and non-inductiveload. The more resistance is included in this circuit the greater effect is obtained on non-inductive loads and the less on inductive loads. The action of the devices shown in this figure maybe understood by reference to Figs. 5 and 6, which are diagrams of the electromotive forces and currents in the system. In Fig. 5 the vector 1 2 represents in magnitude and phase the electromotive force impressed upon the system by the armature of the main machine, and 1 3 represents the current lagging by the angle 0. The current in the primary of the shunt-transformer may be represented by 1 4, lagging behind the electromotive force by a nearly constant angle. The amount of this lag may be fixed in any given case by properly proportioning the resistance and self-induction of the windings. The secondary electromotive force of this transformer will be nearly in opposition to the electromotive force impressed upon the system and may therefore be represented by 1 5. This secondary electromotive force will be nearly constant in phase, but will tend to fall slightly in mag nitude as the load comes on and as the selfinduction of the external circuit increases in machines which are not provided with regu lating devices; but when my improved regulator is used and adjusted for overcompounding it will rather tend to rise. The current 1 3 in liowing through the series transformer and through the resistance It will divide into two components 1 6 and 1 7, nearly at right angles to each other. 1 6 represents the current in the primary of the series transformer lagging behind 1 3, and 1 7 the current in the resistance R leading l 3. It will be seen that the resistance R acts as a phase-shifting device. The electromotive force across the primary of the series transformer will be found to be nearly in phase with 1 7, owing to the fact that the resistanceR is non-inductive. The secondary electromotive force of the series transformer will be nearly in opposition to its primary electromotive force and may be represented by 1 8. The two electromotive forces 1 5 and 1 8 are in series, but reversely connected, as will be seen by examination of the connections in Fig. 7-that is to say, the primaries of the two transformers are so connected that when the upper terminal of N receives positive current from the right-hand main the upper terminal of N receives negative current from the same main, and vice versa. e therefore reverse 1 8 in the diagram and have 1 9 and 1 5 as the two electromotive forces acting to produce current in the regulator. At no load the electromotive force 1 5 of secondary it acts alone. If a non-inductive load comes on the system, the electromotive force 1 9 of the secondary n will be added to the electromotive force 1 5 and the current in the solenoid B will be due to the resultant 1 10, which within a certain range of load grows smaller as the current in the series transformer rises. It will be seen that this result is due to the fact that the angle 9 1 5 is greater than a right angle. It is obvious that the transformers should be so designed that the range of load within which the resultant 1 1O grows smaller as 1 9 rises is well Within the range of load for which the generator is designed. If the load becomes inductive, the condition of things will be as shown in Fig. 6. The angle 6 has now increased and the vectors 1 6, 1 7, 1 8, and 1 9 are correspondingly displaced. The result is that 1 9 has come more nearly in opposition with 1 5 and the resultant 1 10 is decreased in magnitude.

It will be seen that the action is to decrease the current in the solenoid as the load or lag upon the circuit increases. This decrease in the current in the solenoid will cause an increase in the field excitation of the main generator, as above set forth, and the device will act to maintain constant electromotive force at any desired point upon the line, according to the design of the apparatus and the value of the non-inductive resistance R.

In Fig. 8 the arrangement is very similar in principle; but in this case my improvements are applied to regulate the electromotive force of a feeder by varying the amount and sign of its boosting. The rheostat R is replaced by a feeder-regulator FR, which may be of the form shown in the patent to Steinmetz, No. 5%,400, dated October 22, 1895, or of any other approved form. The primary of the series transformer, still shunted by the resistance R, is connected in series with the circuit, as shown, and as the load or lag on the feeder increases the current in the solenoid B decreases, as above explained, with the result that the electromotive force in the feeder is varied to maintain constant voltage at any selected point on the system whatever may be the conditions of the circuit.

The form shown in Fig. 9 is similar to that of Fig. 7, but With the series transformer and its connections omitted. It will be seen that as the terminal voltage of the generator drops from any cause whatever the current in the solenoid B weakens, 'Which causes the regu-.

lator to adjust the resistance-box A in such a Way as to strengthen the field of the generator.

The arrangements which I have pointed out maybe adapted to the purposes of the engineer in Ways well understood in the art. When the resistance around the series coil is changed, as already pointed out, the proportion of compounding or overcompounding with respect to the inductance of the load is changed, and these effects may be so proportioned that the same compounding effect may be produced with either inductive or non-inductive load, or such desired difference may be obtained as is best suited to the pur pose of the installation.

I therefore claim as my invention and desire to secure by Letters Patent 1. The combination with an electric circuit of a shunt-transformer, a series transformer shunted by a phase-shifting device, and a circuit connecting the secondaries in series, with their electromotiveforces in partial opposition.

2. The combination with an electric circuit, of a regulating device for said circuit, and a magnet responsive to variations in the lead and lag of said circuit and operating the regulating device so as to increase the impressed electromotive force of the circuit With lagging current, and decrease it with leading current.

3. The combination with an electric circuit of a shunt-transformer, a series transformer shunted by a phase-shifting device, a'magnet actuated by the differential action of the seeondarie's of the transformers, and a regulating apparatus for controlling the conditions of the circuit actuated by the magnet.

4. The means for compounding alternating-current dynamo-electric machines or circuits herein set out, consisting of a transformer having its primary connected across the mains, a second transformer with its primary in series with the mains, a resistance shunting the series transformer, the secondaries of the transformers being in series and with their electromotive forces in partial opposition, and a potential-regulator controlled by the current in the secondary circuit.

5. The means for compounding alternating-current dynamo-electric machines or circuits herein set out, consisting of a series transformer shunted by a resistance, a shunttransformer with its secondary in series with the secondary of the series transformer, a solenoid in the secondary circuit, a resistance in the exciter-circuit of the dynamo-electric machine, and means controlled by the solenoid for changing the resistance.

6. In combination, a series transformer shunted by a resistance, a shunt-transformer, the secondaries of the two transformers being in series, an electromagnetic device in the secondary circuit, a constantly-running shaft, a potential-regulator, and means interposed between the shaft and the regulator and controlled by the electromagnetic device for shifting the regulator in one direction or the other.

7. In combination, an alternating-current dynamo-electric machine, an exciter, a resistance in the exciter-circuit, a constantlyrunning shaft, a solenoid, a connection between the shaft and the resistance controlled by the solenoid, a series transformer shunted by a phaseshifting device, a shunt-transformer, and a circuit including the secondaries of the two transformers and the solenoid in series.

In Witness whereof I have hereunto set my hand this 26th day of October, 1896.

EDWARD B. RAYMOND.

Witnesses:

B. B. HULL, O. L. HAYNES. 

